JP6356347B2 - Method for blowing a displacement reducing agent into a blast furnace - Google Patents

Description

  The present invention is a method for pneumatically blowing a powdered replacement reducing agent into a gasification reactor or into a blast furnace through a tuyere into a blast furnace in a high-density flow process, It relates to a process which is gasified during the reaction. In another aspect, the present invention provides that the replacement reducing agent is blown by a transport gas through the first injection lance, in addition to the replacement reducing agent and the transport gas, in the opening region of the injection lance, the replacement reducing gas and It relates to a method of supplying oxygen combined with a transport gas. The invention also relates to a device for carrying out this method.

  Supplying liquid, gas, and / or solid displacement reducing agent or fuel to the blast furnace process via tuyere (and blast pipe) instead of the relatively costly blast furnace coke is “stahl und As described in a paper entitled “eisen” [Steel and Iron], 133 (2013) no. 1, pp. 49-62, it is basically used in the production of crude iron in a blast furnace. Yes. In this specification, the term “replacement reducing agent” is used uniformly to cover all reducing agents and carbon-containing fuels such as coal. In the context of the present invention, the solid displacement reducing agent may comprise not only coal and coke dust, but also crushed plastic waste as described in DE 19859354. Of particular importance here is that solid particles do not penetrate the coke bulk whenever possible. Otherwise, the gasification reaction is interrupted, resulting in an interruption of the blast furnace process. Hot blasting forms a spiral region where the injected displacement reducing agent mixes with the hot blast of the tuyere. In order to prevent solid particles from penetrating into the coke bulk, the entire injected solid displacement reducing agent is removed from the injection lance and before the end of the swirl zone, i.e. before it hits the coke bulk. In addition, it must be gasified during flight.

In the context of the present invention, the term “gasification” means incomplete combustion, preferably producing CO and / or H ₂ . In contrast, “combustion” means complete combustion, for example, where CO ₂ and H ₂ O are produced. CO and H2 are particularly useful for blast furnace processes, and the purpose of injecting the displacement reducing agent is a gasification reaction, from which the reaction product saves particularly high cost coke fuel Leads to.

  In the area of gasification reactions, the purpose of the gasification reaction is usually the production of reducing gas obtained as a product from the gasification reactor. However, in the blast furnace process, reducing gas is used to obtain crude iron such as iron ore.

  In a well-known method, for example, carbon-containing powdered substitution reducing agents such as coal dust are converted into nitrogen by the inert transport gas, a paper entitled “STEEL & METALS Magazine”, Vol. 27, no. 4, 1989, pp. Supplied pneumatically by high density flow or flight flow to the tuyeres of the blast furnace through one or more transport lines as described in 272-277 and German Patent No. 3603078. Here, the replacement reducing agent is injected using oxygen by at least one single injection lance constituting a pipe protruding from the tuyere or by at least one coaxial injection lance projecting into the tuyere.

  "Chemie Ingenieur Technik" [Chemical Engineering] 84 (2012), no. 7, p. 1076-1084, for example, describes a coaxial injection lance, which preferably comprises an inner pipe for coal transportation and An outer pipe that coaxially surrounds the inner pipe to form a ring gap; As described in German Patent No. 4008963, oxygen is introduced through the ring gap.

  It is also well known to use an injection lance including three pipes nested inside each other instead of a single coaxial injection lance, as described in JP-A-11-92809. There, coal dust is introduced through the inner pipe, oxygen is introduced through a coaxial gap between the inner pipe and the pipe covering the inner pipe, and between the second pipe and the third pipe covering the second pipe. Water vapor or a mixture of water vapor and oxygen dioxide is introduced through the second coaxial gap.

  Inert pure nitrogen gas is usually used as the transport gas. It is therefore advantageous with regard to explosion prevention inside the distribution and injection system and is often readily available in blast furnace plants.

  In addition, in Chinese Patent Publication No. 101000141, Chinese Patent Publication No. 102382915 and Chinese Patent Publication No. 102060197, as much as possible, inert waste gas or carbon dioxide is used for pneumatic distribution and injection of coal dust instead of nitrogen. It is described that it can be used as a transport gas. The purpose of these ideas is to improve environmental protection and energy savings. In these examples, waste gas from a hot blast burner or carbon dioxide as pure as possible is used.

  Also, from other areas of the technology, in the production of synthesis gas by coal dust pressure gasification, pure water carbon dioxide or a mixture of carbon dioxide and nitrogen is used as a medium for providing an inert gas, as well as fluidization and transportation. As a medium, it is supplied to a pneumatic coal dust transport system. An example of this is described in German Patent Publication No. 102007020294.

  As long as nitrogen is used as the transport gas, there is the disadvantage that nitrogen has a reaction stopping and retarding effect on the gasification reaction of the displacement reducing agent. Since the particles of the displacement reducing agent are covered with nitrogen, the reaction starts only when the nitrogen is eliminated. This results in a reaction delay, thus reducing the time suitable for the reaction with respect to the time of flight of the replacement reducing agent and leaving the injection lance intact.

  The very short reaction time of a few milliseconds, which can be used to gasify the displacement reducing agent when injected into the tuyere and blast furnace swirl regions, uses hydrogen as the inert gas, the critical reaction time The possible gasification potential of the displacement reducing agent is not optimally utilized when injected into the blast furnace.

  When carbon dioxide was used as the transport gas, it was observed that there were few reaction terminations. However, the conventionally known methods using carbon dioxide as the transport gas are relatively complex and therefore disadvantageous compared to nitrogen. Further, since a relatively large amount of energy is required to introduce carbon dioxide into the reaction with the substitution reducing agent, carbon dioxide is not optimal for the gasification treatment of the substitution reducing agent.

  It is an object of the present invention as a whole to provide a gasification reactor, a blast furnace, and a gasification reaction of a substitution reducing agent as quickly and effectively as possible in order to increase the achievable injection of the substitution reducing agent in the reactor. Or to build a method for blowing the displacement reducing agent into other reactors. In particular, in a blast furnace, the overall fuel cost is further reduced while further reducing coke efficiency and fuel efficiency depending on coke / coal or fuel / replacement reducing agent conversion factors.

  This object is achieved by a method according to claim 1, claim 2 or claim 8 and a device according to claim 15. Advantageous embodiments of the invention are described in the dependent claims.

  In accordance with a first aspect, the present invention is a method for pneumatically blowing a powdered displacement reducing agent in a high density flow process with a transport gas in a reactor, particularly a gasification reactor, through a tuyere and into a blast furnace. Thus, a method is provided in which the replacement reducing agent is gasified by a gasification reaction.

  In the context of the present invention, the term “high density flow process” means the process described in “STEEL & METALS Magazine”, Vol. 27, no. 4,1989, pp. 272-277. With respect to the present invention, the high density flow process is distinguished from the flight flow process in that it is a high density flow of powdered material of 60% or more, particularly preferably 80% or more of the packing density in the bulk state. . In contrast, the flight flow process is performed at a flow density of 25% or less.

In accordance with another aspect of the present invention, the transport gas includes a fuel gas and its component (eg, O ₂ , H ₂ O or CO ₂ ) or its oxide component (ie, undergoes an oxidation reaction prior to the gasification reaction). CO, H ₂ , CH ₄ ) are at least partly involved in the gasification reaction of the substitution reducing agent and other gases or gas mixtures. The other gas or gas mixture is different from the fuel gas, so that, according to the first aspect of the present invention, the transport gas consists entirely of components other than the fuel gas.

  According to another aspect of the invention, the transport gas is carbon dioxide, hydrogen, water vapor, oxygen, hydrocarbons or mixtures thereof, in particular natural gas, combustion gas, coke gas, or coke plant gas, conversion gas, Furnace gas or other blast furnace gas or mixtures thereof. According to this other aspect, the transport gas may also consist of complete fuel gas.

  In principle, the transport gas has to be considered as an injection, ie an injection with a composition injected into the gasification reactor or injected into the blast furnace via the tuyere.

  In the context of the present invention, the term “fuel gas” is itself a combustible component or a gas having a component whose oxidizing component participates in the gasification of the replacement reducing agent during the gasification of the replacement reducing agent. Means. Fuel gas includes carbon monoxide, which is carbon dioxide, hydrogen, steam, oxygen, hydrocarbons or mixtures thereof, in particular natural gas, combustion gas, coke gas, coke plant gas, conversion gas, or other blast furnace gas Alternatively, it can be applied to a mixture thereof. The reaction that forms the basis for gasification has already been ignited early and more time is available than if the replacement reducing agent is covered by nitrogen, so the fuel gas is a substantial part of the gasification reaction of the replacement reducing agent. Invite a certain acceleration. In many fuel gases, in some cases, the use of fuel gas as the transport gas allows a blast furnace process or other reaction process to be configured more efficiently. For example, if a carbon-containing gas is introduced into the blast furnace as a fuel gas during the injection of the replacement reducing agent, this can save a limited but expensive coke. However, in the context of the present invention, the fuel gas is a gas that directly or indirectly participates in the gasification of the displacement reducing agent, independent of possible additional involvement in the reaction process in the reactor, in particular the blast furnace process.

  A supply of fuel gas of only 2% by weight results in a suitable pre-ignition and accelerated gasification of the displacement reducing agent, and an increase in the proportion of fuel gas in the transport gas leads to a further increase in efficiency. Along with the fuel gas ratio, the temperature and pressure in the vicinity of the injection point, in particular the swirl region, are important for the time of ignition. Depending on the prevailing conditions, it is advantageous to further increase the fuel gas ratio. Therefore, it is possible to inject more replacement reducing agent per unit time than when conventional nitrogen is used.

  Preferably, the transport gas is composed of at least 2 wt%, preferably at least 5 wt%, more preferably at least 10 wt% fuel gas. The transport gas is composed of up to 90% by weight, preferably up to 50% by weight, more preferably up to 25% by weight and even more preferably up to 20% by weight of fuel gas. Therefore, the weight ratio of the fuel gas in the transport gas is preferably between 2% and 90%, more preferably between 2% and 50%, between 2% and 25% or between 2% and 20%. Is more preferred, between 5% and 90%, between 5% and 50%, between 5% and 25%, between 5% and 20%, between 10% and 90%, 10% More preferably between 10% and 50%, more preferably between 10% and 25%.

  Moreover, according to the 1st aspect of this invention, transport gas may consist of gas other than fuel gas, or mixed gas. The other gas or gas mixture preferably consists of nitrogen. However, other gases and fuel gases may be included in the transport gas. Preferably, these other gases must provide sufficient protection against explosions and ensure that they do not adversely affect the blast furnace process, particularly the gasification process of the displacement reducing agent. .

In particular, in the context of the present invention, the following reactions should be related as a gasification reaction of the replacement reducing agent (coal dust gasification reaction).

  In particular, the present invention relating to a method for blowing a carbon-containing powdery reducing agent or fuel into a gasification reactor or blast furnace is provided that if the powdery reducing agent or fuel used in the process is supplied to the reactor, Depending on its type, it can be used in all technical areas in processes that are advantageously influenced in relation to the method, energy or economy. This is because the beneficial effect of using a replacement reducing agent or fuel can be amplified by a possible increase in the injection rate of the replacement reducing agent or fuel. The present invention is therefore not limited to blast furnaces or gasification reactors, but can be applied to other reactors. In addition to gasification reactors and blast furnaces, these reactors are, for example, shafts or smelting iron furnaces, fluidized beds, hot air furnaces and combustion chambers, for example SAF (submerged arc furnace) or EAF (electric arc furnace) plants. It can be applied to subsidize electric energy. However, gasification reactors and in particular blast furnaces are preferred applications of the method according to the present invention because simple modifications to existing plants result in increased efficiency.

  Preferably, the transport gas and displacement reducing agent are blown through at least one injection lance that preferably projects into the tuyere or the corresponding chamber of the reactor or gas pipe. With this injection lance, the displacement reducing agent and the transport gas are well mixed by the hot blast furnace. However, it is alternatively possible that the replacement reducing agent is injected by the transport gas through a simple opening in the tuyere.

  More preferably, oxygen gas or an oxygen-containing gas mixture is injected into the reactor, in particular a blast furnace, and the transport gas and displacement reducing agent are combined with the oxygen or oxygen-containing gas mixture in the open region of the first injection lance. .

  In an advantageous embodiment of the invention, the first injection lance preferably comprises an inner pipe and an outer pipe surrounding the inner pipe, is formed with a ring gap, and a displacement reducing agent is introduced through the inner pipe by the transport gas. Oxygen or oxygen-containing gas mixture is introduced through the ring gap.

  Thus, the injected displacement reducing agent is covered with pure oxygen or oxygen mixed gas immediately after it originates from the first injection lance. Thus, the reaction partner important for the gasification reaction, i.e. the fuel gas contained in the oxygen, the displacement reducing agent and the transport gas, is transferred between the displacement reducing agent, the transport gas and oxygen in the region of the first injection lance. , Combined at the interface critical to reaction ignition.

  The required reaction energy is given first by the back flow from the reactor, in particular from the reaction chamber of the blast furnace, and second by the gasification reaction itself that starts thereafter. Here, in particular, the fuel gas preferably requires as little energy as possible to ignite the gasification reaction. In this context, carbon monoxide and hydrogen are advantageous over carbon dioxide and water vapor. Because they require a lower temperature to ignite the gasification reaction.

  According to an alternative advantageous embodiment, the first injection lance consists of a single pipe, through which the displacement reducing agent is introduced by the transport gas. Oxygen or oxygen-containing gas is then suitably fed to the replacement reducing agent in the tuyere via a different introduction route, for example via an additional gas lance, a second injection lance or a hot blasting route through the tuyere Is done.

  In this way, all partners of the gasification reaction are brought together in the open area of the injection lance, but the advantageous embodiment described above with coaxial pipes is simply controllable of the displacement reducing agent, transport gas and oxygen and Enable more efficient supply.

  In accordance with the second aspect of the present invention, in a high-density flow process, the powdered displacement reducing agent is blown pneumatically by a transport gas into a reactor, particularly a gasification reactor, or through a tuyere into a blast furnace, As a result, a method is provided in which the replacement reducing agent is gasified in a gasification reactor. In addition to the displacement reducing agent, transport gas and oxygen are supplied through the first injection lance and combined with the displacement reducing agent and the transportation gas in the opening region of the first injection lance. Here, the first injection lance preferably has an inner first pipe and a second pipe arranged around it, so that a ring gap surrounding the first pipe is between the first and second pipes. The replacement reducing agent and the transport gas are introduced through the first pipe, and the oxygen is introduced through the ring gap. In accordance with this aspect, the transport gas includes a fuel gas, the component or the oxide component of which is at least partially involved in the gasification reaction. In the method according to the second aspect of the present invention, the energy threshold required for ignition is reduced compared to the method described above in which the fuel gas comes into immediate contact with oxygen. In this case, for example, water vapor or carbon dioxide can also be efficiently used as the fuel gas.

  When oxygen is additionally added through the second pipe that forms the ring gap, particularly good gasification of the replacement reducing agent is possible.

  Preferably, several injection lances can be used. Alternatively and additionally, several secondary injection lances are preferably used. Several first and / or second injection lances may be provided in one or several tuyere.

  The flow of supplied oxygen or oxygen-containing gas and / or supplied replacement reducing agent is advantageously mixed or swirled in the opening region of the first injection lance. In this regard, it is preferred that the mixing of the replacement reducing agent and the transport gas with oxygen be facilitated by a spiral structure.

  The vortex flow in the reaction chamber ensures better mixing of the reaction partners, thereby resulting in faster and more efficient gasification of the injected displacement reducing agent.

  In this regard, the first injection lance preferably has a spiral structure that facilitates the mixing of the oxygen-containing fuel gas and the displacement reducing agent within the open region of the first injection lance. This spiral structure may be, for example, the configuration of a guide plate in the opening area of the first injection lance. Other swirl structures that produce a vortex of a replacement reducing agent or hot blast are also possible instead of or in addition to oxygen. This structure is in principle independent of the injection lance, but can be used particularly effectively in connection with the injection lance.

  The present invention, particularly preferred embodiments, avoids the quenching and delaying effects of nitrogen inert gases conventionally used in gasification reactions of displacement reducing agents. Thereby, the speed of the gasification reaction of the substitution reducing agent is accelerated. This effect is further amplified by pure oxygen or an oxygen-containing mixture supplied to the open area of the injection lance, and the reaction rate is further accelerated. A further important factor for accelerating the gasification reaction is the early ignition of the injected reductant immediately after leaving the injection lance, for example in the hot blast flow from the blast furnace. In order to achieve this, the coating of the injected substitution reducing agent with oxygen or an oxygen-containing mixture takes advantage of the physical property that the transport gas absorbs radiation while it is thermally permeable. As a result, heat radiation from reactors such as hot blasting, tuyere walls, and blast furnace swirl zones are transmitted almost unimpeded through the oxygen coating, and the energy required to ignite the displacement reducing agent is oxygen and displacement. Released at the reducing agent plus fuel gas interface. The energy used to ignite the replacement reductant is therefore released directly into the replacement reductant dust particles and the fuel gas involved in the gasification reaction at the right location, ie at the interface, due to the radiation absorption that occurs there.

  In general, the preferred embodiment follows the coke / coal conversion factor to keep the time required for gasification of the displacement reducing agent remaining injected into the reactor, particularly the tuyeres and swirl zones of the blast furnace. While reducing the coke rate, it also increases the maximum possible injection. Therefore, the fuel cost for blast furnace operation is reduced.

  In a further preferred embodiment of the method, the supplied displacement reducing agent and / or transport gas and / or suitably supplied oxygen or oxygen-containing gas is preheated to a temperature between 100 ° C. and 950 ° C. Including that.

  By preheating the reaction partner, the heating time interval after injecting the reactants into the reaction chamber (tuyere and swirl zone) is omitted, and thus the overall gasification reaction takes place faster, so Gasification is further accelerated. It makes it possible to further increase the injection rate of the convertible displacement reducing agent.

  The charge of the transport gas for the reactor, in particular the displacement reducing agent injected into the blast furnace, can be varied over a wide range and can be adjusted depending on the reactor. By changing the ratio of the amount of displacement reducing agent to the amount of fuel gas, the ratio can be set to optimize the gasification of the displacement reducing agent, and each of the reactors, in particular the blast furnace or gasification reactor, respectively. As a function of their operating state, their individual configuration, raw materials used, and atmospheric conditions.

  For the process according to the invention, the exhaust rate and / or the amount of displacement reducing agent injection and / or the applicable exhaust rate and / or the amount of oxygen from the injection lance can be varied within a wide range, depending on the reaction. It is further advantageous if it is adjustable. In this case, an optimum ratio can be set for the gasification reaction of the replacement reducing agent in combination with the fuel gas, in addition to and in addition to the above-mentioned changes in the charge of the transport gas with respect to the replacement reducing agent. The applicable oxygen may vary depending on the respective operating conditions of the reactor, in particular the blast furnace or gasification reactor. This is especially true when the pumping speed and / or the amount of oxygen are changed taking into account the reaction at a pre-set pumping speed and / or the amount of oxygen in order to set the optimum parameters for the gasification reaction of the displacement reducing agent. It means that it is possible.

  Depending on the design of the reactor, for example blast furnace, in particular tuyere and injection mechanism, or gasification reactor, and depending on the fuel gas used, the charge of the transport gas, i.e. between the fuel gas and the displacement reducing agent It is possible to substantially optimize the mass flow ratio between. A lightning phenomenon occurs in the replacement reducing agent due to the fuel gas, particularly when oxygen is supplied to the reaction chamber. Sufficient displacement reducing agent may be supplied to extinguish this lightning phenomenon. In order to maximize the amount of displacement reducing agent to be supplied, the supply amount of fuel gas and / or applicable oxygen, and the exhaust rate of the displacement reducing agent, fuel gas and / or oxygen are as high as possible for the displacement reducing agent. It can be adjusted so that lightning phenomenon is observed at a large supply amount.

  In embodiments where lightning does not occur or cannot be observed, the operating parameters of the reaction process, in particular the blast furnace process, are used to determine the maximum supply of replacement reducing agent, the supply of fuel gas and / or oxygen, the replacement reducing agent, the fuel gas and In principle, it is possible to find the optimum value in the arrangement required for the oxygen pumping speed.

  Preferably, the fuel gas consists of natural gas, furnace gas, coke gas, or coke plant gas, conversion gas or other furnace gas or mixtures thereof. In particular, furnace gas and coke gas are fuel gases that are readily available in large quantities in the vicinity of the blast furnace and are therefore particularly suitable as fuel gases. In addition, these gases occupy a large proportion of the components involved in the gasification reaction of the substitution reducing agent through itself or its oxidizing component.

  In particular, carbon dioxide and water vapor impose increased requirements on the reaction state for use as fuel gas. These components have higher energy requirements than, for example, carbon dioxide or hydrogen, to dissociate oxygen from these molecules, that is, to create a preferred gasification environment for the gasification of the displacement reducing agent. Accordingly, these fuel gases are preferably used in the open area of the injection lance, especially when additional oxygen is supplied in the highest possible concentration.

  Overall, the method according to the invention, in particular the preferred embodiment, leads to improvements in the blast furnace process or related processes with respect to method, energy and economy.

  A device according to the invention for carrying out the method described above comprises an injection lance for blowing a displacement reducing agent into a reactor, in particular a blast furnace gasification reactor or tuyere, a transport gas and / or a displacement reducing agent. And a transport line for supplying displacement reducing agent from the vessel to the injection lance. The device further comprises a fuel gas supply, through which fuel gas is supplied to the transport gas upstream of the injection lance.

  Thus, the device according to the invention has a fuel gas supply in which the fuel gas is supplied to the transport gas in a predetermined weight ratio in addition to the other gases for transport of the displacement reducing agent. This fuel gas supply is arranged in a region upstream of the injection lance so that the transport gas and fuel gas are injected through the injection lance into the reactor, in particular into the blast furnace tuyere or gasification reactor. In principle, it is possible to supply fuel gas to the transport gas at any point along the transport line upstream of the injection lance or in the vessel. Also, the pressure required for the supply is lower and the supply to the injection lance occurs closer. Preferably, the fuel gas supply is arranged on a transport line, and particularly preferably the distance along the transport line from the fuel gas supply to the injection lance is the displacement reducing agent and other applicable to the transport gas. Shorter than the distance along the transport line to the vessel where the gas is stored. Advantageously, the fuel gas supply is arranged immediately in front of the injection lance. More preferably, in a transport pipe having a distribution device, the fuel gas supply is arranged downstream of the distribution device.

  Other features and advantages of the invention will be apparent from the claims and the description with reference to the following drawings.

FIG. 1A schematically shows a suitable injection plant for a blast furnace. FIG. 1B shows in detail the injection plant of FIG. 1A. FIG. 1C shows the injection plant of FIG. 1A in detail. FIG. 2 shows a suitable injection plant with a static distributor. FIG. 3 shows a preferred injection plant having a distribution vessel instead of a static distributor.

  The same or corresponding elements are described with the same reference numerals only once in the drawings. In principle, features described in relation to one embodiment can also be implemented in other embodiments. This applies in particular to the arrangement and configuration of valves, chokes or distributors that affect the flow, and to the configuration of the mechanism for injecting the displacement reducing agent into the tuyere.

  FIG. 1A is a schematic diagram of a preferred injection plant 100. Injection plant 100 has tuyere 7 through which hot blast is injected from blast ring 8 into the blast furnace. Arranged at the tuyere 7 is an injection lance 6, preferably configured as a coaxial dust and gas injection lance, through which a first flow of displacement reducing agent and a transport gas containing fuel gas, and oxygen or A second flow containing oxygen-containing gas is simultaneously fed to the hot blast in a high density flow process.

  In the illustrated embodiment, the injection lance 6 is coupled to a separate transport line 5 through which the displacement reducing agent is transported from the injection vessel 3 via the fluidized vessel 4 to the injection lance 6. Preferably, the blast furnace plant has several injection lances 6 and in order to inject as much substitution reductant as possible as uniformly as possible, with individual transport lines 5 and in some cases several fluids. It has a chemical vessel 4.

  In FIG. 1A, shown upstream of the injection vessel 3 is a pressure lock 2 through which the pressurized injection vessel 3 is optionally supplied with the replacement reducing agent added thereafter. For example, the pressure lock 2 is filled with coal dust or other displacement reducing agent under atmospheric pressure, the pressure lock 2 is then brought to the dispensing pressure of the injection vessel 3 and then the displacement reducing agent is injected into the injection lance vessel 3. Introduced in. In order to control this, in FIG. 1A, shut-off valves 1 are arranged upstream and downstream of the pressure lock 2. Although valves are described herein as examples, other flow restriction elements may be supplemented, modified, replaced, or partially omitted.

  In FIG. 1A, for example, “A” is marked at a location where transport gas and / or fuel gas is introduced into the system. In the embodiment shown in FIG. 1A, a replacement reducing agent or fuel may be introduced into the system at the location of the mark “B” upstream of the first shutoff valve.

  In the region of the point “A” of the individual transport line 5, preferably a fuel gas is added to the transport gas, so that the transport gas consists, for example, of at least 2% by weight of fuel gas, its components or The oxide component is at least partially involved in the gasification reaction of the displacement reducing agent in the tuyere 7 and in the blast furnace. Fuel gas may be preferably introduced into the system at one or both of the points “A” on the individual transport line 5, so that the transport gas downstream of this point is at least 2% by weight of fuel gas. And the remaining other gases or other gas mixtures, and thus a particularly effective injection of the displacement reducing agent in the context of subsequent gasification.

  In the embodiment shown in FIG. 1A, oxygen is supplied to the injection lance 6 at the point of the mark “C” immediately upstream of the injection lance 6. In the embodiment shown in FIG. 1A, the injection lance 6 preferably introduces a replacement reducing agent with transport gas, containing at least 2% by weight of fuel gas, into the tuyere 7 through a central pipe surrounded by a ring gap. Through this, oxygen or oxygen-containing gas is injected into the tuyere 7 as a casting flow of transport gas.

  This configuration of the injection lance 6 results in a particularly effective gasification reaction that proceeds particularly fast and ignites particularly fast, thus allowing the addition of a particularly large amount of displacement reducing agent, in particular a large amount of high quality and expensive blast furnace coke. Brings savings.

  FIG. 1B shows an alternative embodiment of the injection mechanism, which has a single dust injection lance 16 and a single gas injection lance 17. The replacement reducing agent having the transport gas is injected into the tuyere 7 through the dust injection lance 16, and oxygen is injected through the gas injection lance 17.

  Preferably, at the point of the mark “A” immediately before the single dust injection lance 16, fuel gas is supplied to the displacement reducing agent and the transport gas. However, substantially further upstream of the point shown in FIG. 1B, the fuel gas is already contained in the supply system, and the replacement reducing agent that already contains the fuel gas is partially or completely carried by the transport gas. Is possible.

  FIG. 1C shows another preferred embodiment where only a single dust injection lance 16 is provided and no guided injection of oxygen is provided. Here, oxygen is supplied by the corresponding enrichment of the hot blast via the blast ring 8 or is taken from the hot blast without a separate enrichment to carry out the gasification reaction of the replacement reducing agent. .

  FIG. 2 shows an alternative embodiment of the injection plant 200.

  In contrast to the injection plant of FIG. 1A, FIG. 2 shows an injection plant 200 that does not have a separate pressure lock. However, this separate compression lock may also be provided in the embodiment according to FIG. In the injection system 200, in particular, two separate injection vessels 3 may be provided and there may be more than one injection vessel 3. As shown in the embodiment of FIG. 1A, from the injection vessel 3, the displacement reducing agent and the transport gas enter the pipe system via the respective fluidization vessel 4.

  The injection plant 200 has, for example, two collective transportation lines 9. In principle, a single collective transport line 9 may be provided, or two or more collective transport lines 9 may be provided. Through the collective transport line 9, the displacement reducing agent and transport gas from the fluidized vessel 4 arrive at the static distributor 10 where they are distributed to several individual transport lines 5. Each of the transport lines 5 is then led to an injection lance 6 respectively. This injection plant 200 may also be configured and modified as described in relation to FIG.

  Preferably, each of the transport lines 5 has a choke 20 for reliably adjusting the distribution of displacement reducing agent to be injected. Alternatively or additionally, the individual transport line 5 may comprise a control valve.

  Particularly preferably, the fuel gas is added to the transport gas at the point of the mark “A” on the individual transport line 5. However, in principle, the fuel gas can also be supplied upstream of these points. For example, it may be supplied in the region of the collective transportation line 9 or directly to the injection vessel 3. However, from the viewpoint of safety, the fuel gas is preferably supplied to the transport line as downstream as possible. In particular, in this case, the risk of explosion of the injection plant can be kept very low.

  FIG. 3 shows another preferred embodiment of the injection plant 300. The injection plant 300 according to FIG. 3 has three injection vessels 11 instead of the injection vessels of the two embodiments described above.

  From the intermediate transport vessel 11, the displacement reducing agent and the transport gas reach the distribution vessel 12 through the collective transport line 9. From the distribution vessel 12 through the fluidization vessel 4 in the same manner as in the embodiment described above, the displacement reducing agent with the transport gas is injected into the injection lance 6 through a separate transport line 5 for injection into the tuyere 7. be introduced. Instead of the injection lance 6, in this embodiment, another mechanism for blowing the replacement reducing agent into the tuyere 7 may be used.

  Excess gas may be released from the distribution vessel 12 into the atmosphere via a gas control valve 14 installed downstream of the filter 13. The injection plant 300 of the third preferred embodiment also includes several valves, in particular a shut-off valve 1 and a dust control valve 15 to allow reliable control of the displacement reducing agent and transport gas. For the sake of completeness, this valve, in particular the dust control valve 15, may be provided on a separate transport line 5, or on the collective transport line 9 or on a plurality of lines 9. In connection with the present invention, no requirements are imposed on the arrangement and configuration of valves, vessels and similar components, and the configuration of the gas transport system. These arise in principle from the design of well-known injection plant professionals.

  In the embodiment shown in FIG. 3, the fuel gas is supplied to the transport gas particularly preferably at the mark “A” point on the individual transport line 5. It is also possible to add fuel gas to the system at other points, similar to the embodiment described above according to FIGS. For example, in FIG. 3, various points may be marked as point “A” for adding fuel gas to the system.

  The above-described embodiments show three examples of how the method according to the present invention is implemented in a plant. However, the present invention is not limited to these specific examples of injection plants and can be used with different types of devices.

  In particular, the injection lance embodiments may be selected individually for each injection plant and combinations thereof. The embodiment illustrated in connection with FIG. 1 can also be used for the embodiments shown in FIGS. 2 and 3 and may be combined arbitrarily.

  The method according to the present invention can be applied using the above-described injection plant. In this case, it becomes possible to achieve a substantial savings in fuel costs of the blast furnace process or gasification reactor, so that the gasification reaction according to the invention proceeds faster and ignites faster, so that the prior art method A greater amount of displacement reducing agent than is injected into the blast furnace or reactor.

German Patent Publication No. 19859354 German Patent No. 3603078 German Patent No. 4008963 JP-A-11-92809 Chinese Patent Publication No. 101000141 Chinese Patent Publication No. 102382915 Chinese Patent Publication No. 102060197 German Patent Publication No. 102007020294

“Stahl und eisen” [Steel and Iron] 133 (2013) no. 1, pp. 49-62 "STEEL & METALS Magazine", Vol. 27, no. 4, 1989, pp. 272-277 "Chemie Ingenieur Technik" [Chemical Engineering] 84 (2012), no.7, p. 1076-1084

Claims (29)

In a high-density flow process in which the flow density of the powdery reducing agent is 60% or more of the packing density in the bulk state, the powdery reducing agent is transferred into the reactor by the transport gas or Pneumatically blown into the blast furnace through the mouth (7), and as a result, the replacement reducing agent is gasified in the gasification reaction,
The transport gas includes a fuel gas composed of carbon monoxide, hydrogen, water vapor, oxygen, hydrocarbon, furnace gas, natural gas, coke gas, conversion gas, other blast furnace gas, or a mixture thereof. Method. In a high-density flow process in which the flow density of the powdery reducing agent is 60% or more of the packing density in the bulk state, the powdery reducing agent is transferred into the reactor by the transport gas or Pneumatically blown into the blast furnace through the mouth (7), and as a result, the replacement reducing agent is gasified in the gasification reaction,
The transport gas is characterized in that its component or its oxide component comprises a fuel gas that is at least partially involved in the gasification reaction and another gas or gas mixture other than the fuel gas.   The method according to claim 1, wherein the reactor is a gasification reactor.   The method according to any one of claims 1 to 3, wherein the transport gas includes 2% by weight or more and 90% by weight or less of the fuel gas.   The method according to any one of claims 1 to 4, wherein the transport gas contains 5% by weight or more and 50% by weight or less of the fuel gas.   The method according to any one of claims 1 to 5, wherein the transport gas includes 10% by weight or more and 25% by weight or less of the fuel gas.   The method according to claim 1, wherein the transport gas includes 10% by weight or more and 20% by weight or less of the fuel gas.   The method of claim 2, wherein the other gas comprises nitrogen.   9. A method according to any one of the preceding claims, characterized in that the displacement reducing agent is injected with the transport gas through a first injection lance (6, 16).   10. Method according to claim 9, characterized in that the first injection lance (6, 16) projects into the tuyere (7).   In addition to the displacement reducing agent and the transport gas, oxygen is supplied to the reactor through the first injection lance (6), and in the opening region of the first injection lance (6), the displacement reducing agent and the transportation gas The method according to claim 9 or 10, wherein the methods are combined. The first injection lance (6) has an inner first pipe and a second pipe disposed therearound, thereby enclosing the first pipe between the first and second pipes. Formed,
The method of claim 11, wherein the displacement reducing agent and the transport gas are introduced through the first pipe, and the oxygen is introduced through the ring gap. The first injection lance (16) is a single pipe;
The method according to claim 9 or 10, characterized in that oxygen is introduced into the reactor through a second injection lance (17).   The method according to claim 13, characterized in that the oxygen is introduced into the blast furnace via the tuyere (7). In a high-density flow process in which the flow density of the powdery reducing agent is 60% or more of the packing density in the bulk state, the powdery reducing agent is transferred into the reactor by the transport gas or Pneumatically blown into the blast furnace through the mouth (7), and as a result, the replacement reducing agent is gasified in the gasification reaction,
By the transport gas, the displacement reducing agent is blown through the first injection lance (6),
In addition to the displacement reducing agent and the transport gas, oxygen is supplied into the reactor through the first injection lance (6), and the displacement reducing agent and the transportation gas are opened in the opening region of the first injection lance (6). Combined with
The first injection lance (6) has an inner first pipe and a second pipe disposed around it, thereby enclosing the first pipe between the first and second pipes. Formed,
The displacement reducing agent and the transport gas are introduced through the first pipe, the oxygen is introduced through the ring gap,
The transport gas comprises a fuel gas, and a component of the fuel gas or an oxide component thereof is at least partially involved in the gasification reaction.   The method of claim 15, wherein the reactor is a gasification reactor. The method according to any one of claims 11 to 16 , wherein further fuel gas is supplied to the displacement reducing agent immediately before the first injection lance .   The method according to any one of claims 11 to 17, wherein at least one of the oxygen exhaust rate and amount is adjusted in accordance with the reaction.   17. A method according to any one of claims 11, 12, 15 and 16, wherein mixing of the displacement reducing agent, the transport gas and the oxygen is facilitated by a spiral structure. The supply amount of the fuel gas and oxygen into the reactor, and the exhaust rate of the replacement reducing agent, the fuel gas and oxygen into the reactor are adjusted according to the reaction in the reactor. 20. A method according to any one of claims 11 to 19 , characterized in that   The method according to any one of claims 1 to 10, wherein mixing of the displacement reducing agent and the transport gas is facilitated by a spiral structure.   The method of claim 1, wherein at least one of the transport gas and the displacement reducing agent has a temperature between 100 ° C. and 950 ° C.   The method according to any one of claims 2 to 21, wherein at least one of the transport gas and the displacement reducing agent has a temperature between 100 ° C and 950 ° C.   The fuel gas includes carbon monoxide, carbon dioxide, hydrogen, water vapor, oxygen, hydrocarbon, furnace gas, natural gas, coke gas, conversion gas, other blast furnace gas, or a combination thereof. 23. A method according to any one of claims 2 to 22. A device (100, 200, 300) for performing the method according to any one of claims 1 to 24, comprising:
An injection lance (6, 16) for blowing the displacement reducing agent into the reactor or into the tuyere (7) of the blast furnace;
A vessel (3, 11) for receiving at least one of the transport gas and the displacement reducing agent;
A transport line (5, 9) for supplying the replacement reducing agent from the vessel (3, 11) to the injection lance (6, 16);
With
The device comprises a fuel gas supply (A) through which fuel gas is supplied to the transport gas upstream of the injection lance (6, 16).   26. The device of claim 25, wherein the reactor is a gasification reactor.   26. Device according to claim 25, characterized in that the fuel gas supply (A) is arranged on the transport line (5, 9).   The distance along the transport line (5, 9) from the fuel gas supply (A) to the injection lance (6, 16) is the vessel (3, 11) along the transport line (5, 9). 28. The device of claim 27, wherein the device is shorter than the distance up to.   28. The fuel gas supply according to claim 25 or 27, characterized in that the fuel gas supply is arranged upstream of the injection lance (6, 16) and downstream of the distribution device (10, 12). The device described.

Images